The subject of this invention belongs to the field of molecular biology.
Genomes range in size from about 4xc3x97106 base pairs (bp) in E. coli to 3xc3x97109 bp in mammals. Determination of the primary structure, i.e., sequence, of the entire human genome, is a challenge of the 20th century. A further challenge for biology is the determination of the entire genomic sequence for characteristic species of the living world. It would allow qualitative progress in explaining the function and evolution of organisms. It would also be a great step forward in the explanation and treatment of many diseases, in the food industry and in the entire field of biotechnology.
Prior Art
Recombinant DNA technology has allowed the multiplication and isolation of short fragments of genomic DNA (from 200 to 500 bp) whereby a sufficient quantity of material for determination of the nucleotide sequence may be obtained in a cloned fragment. The sequence is determined on polyacrylamide gels which separate DNA fragments in the range of 1 to 500 bp, differing in length by one nucleotide. Distinguishing among the four nucleotides is achieved in two ways: (1) by specific chemical degradation of the DNA fragment at specific nucleotides, in accordance with the Maxam and Gilbert method (Maxam, A. M. and Gilbert, W., 1977, Proc. Natl. Acad. Sci., 74, 560); or (2) utilizing the dideoxy sequencing method described by Sanger (Sanger, F., et al., 1977, Proc. Natl. Acad. Sci., 74, 5463). Both methods are laborious, with competent laboratories able to sequence approximately 100 bp per man per day. With the use of electronics (computers and robots), sequencing can be accelerated by several orders of magnitude. The idea of sequencing the whole human genome has been discussed at many scientific meetings in the U.S.A. (Research News, 1986, Science, 232, 1598-1599). The general conclusion was that sequencing is possible only in big, organized centers (a sequencing factory) and that it would take about 3 billion dollars and at least ten years. For the time being the Japanese are the most advanced in organizing components of one such center. Their sequencing center has the capacity of about 1 million bp a day at the price of about 17¢ per bp (Commentary, 1987, Nature, 325, 771-772). Since it is necessary to sequence three lengths of a genome, because of random formation of cloned fragments of about 500 bp, 10 billion bp could be sequenced in approximately 30 years in such a center, i.e., it would take 10 such centers to sequence the human genome in several years.